Distributed systems Module 2 -Distributed algorithms Teaching unit 1 – basic techniques Ernesto Damiani University of Bozen Lesson 1 – Introduction

Distributed Algorithms What is a distributed algorithm? Is it practical? Examples: Napster, Gnutella, etc.

Model basics (1) Anonymous

Model basics (2) With IDs

Model basics (3) Overlay network (mono or bi-directional)

Model basics (4) Ring

Model basics (5) Shared memory

Synchronous vs asynchronous communication model t t+d d: clock period t t+??

Algorithms overview Leader election Shortest path Consensus Secure sum Building blocks –Atomic memory, mutual exclusion, logical clocks FINE